In recent years, medical science and biological engineers have been developing prosthetic devices to replace natural components of the human body. The prothetic devices have as their primary objective the replacement of natural bodily components which may have become diseased or damaged while at the same time preserving the natural bodily function associated with the replaced organ, limb or other body component. The prosthetic replacement of natural body components should not be confused, however, with the natural transplantation of a similar living organ, limb or other body component. Prosthetic devices are totally man-made, being constructed primarily of synthetic materials while transplantation is concerned with the replacement of a natural body organ or component received from a human donor.
The prosthetic devices constructed primarily from such synthetic materials must, of course, be compatible with living human tissue and, additionally, must be capable of performing the bodily function of the removed natural component. A successful prosthetic device will last for an indefinite period of time without noticeable degeneration due to the inherent properties of the synthetic materials utilized. The present invention relates to a type of prosthetic device utilized in a human knee. The knee is a bicondylar joint formed by the articulation between the condyles of the femur and the articular cartrilage of the tibia.
Typical conventional prosthetic devices for the knee are shown in U.S. Pat. Nos. 3,924,277, 4,081,866, 4,207,627, RE. 29,757, and 3,869,731 (the disclosures of which are herein incorporated by reference herein). The major problem associated with the conventional knee joint prosthetic devices is the necessity of surgically removing or altering the articulating cartilage of both the femur and tibia. Additionally, many conventional prosthetic devices require that the device be fixedly secured to the femur and tibia by means of surgical cement or the like. The necessity for removing or altering the femoral and tibial cartilage prior to the implantation of the conventional prosthetic devices increases the cost of surgical services associated with such implantation.
According to the present invention, however, a prosthetic device for a human knee is provided such that the articulating cartilage of the femur and tibia remains totally intact. Additionally, the prosthetic device according to the present invention is not intended to be surgically cemented in place. The device is designed to provide a natural substitute for damaged or diseased components in the knee joint area, such as, for example, arthritic conditions, damage due to automobile or athletic injuries, and the like. The device according to the present invention can be easily manufactured, and more efficiently inserted into the human knee, so that manufacturing costs and the cost of surgical services are reduced compared to the conventional prosthetic devices.
The prosthetic device according to the present invention may be manufactured in varying sizes conforming to the varying sizes of the human body and, in addition, the inherent varying size of the inner and outer condyle of the femur.
Therefore, it is a primary object of the present invention to provide a prosthetic device which may be easily manufactured and quickly positioned by surgical methods, without requiring the surgical removal or alteration of the femur and tibial articulating surfaces. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.